JPH1162706A - Caburetor with starting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize operation performance of an engine by providing a holding means to constrain the valve element of a shut-off valve in an open valve position, and making a structure of this holding means so as to release constraint of the valve element by a valve lever when a throttle valve is opened to a certain opening degree. SOLUTION: If a linear movement part 31 is pulled with a knob against a spring 33 in advance of starting an engine, a valve element 28 is separated from a valve seat 27, and an air passage, a fuel passage part 23 and a mixed air passage part 24 composing an auxiliary passage 21 are connected in series. At this time, a constraining part 38 is moved in a direction to be released from a cut-out groove 37, and is fitted in an engagement groove 36 by a constraining spring 39 when the valve element 28 reaches a fully opened position, so that the linear movement part 31 is constrained in an open valve position. If cranking is carried out under this condition, air and fuel are suctioned by a negative pressure of intake air through the auxiliary passage 21, and is introduced into an intake air passage 5. After that, when a throttle valve 4 is opened wider than a partially opened position, constraint of the linear movement part 31 is released, and the valve element 28 is closed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明はエンジンに燃料を供
給するため吸気管路に設置される気化器、詳しくは冷え
た状態のエンジンの始動、暖機運転更には加速運転を行
なわせるのに適した始動機構を具えている気化器に関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carburetor installed in an intake line for supplying fuel to an engine, and more particularly to a carburetor for starting, warming up, and accelerating a cold engine. The present invention relates to a carburetor having a starting mechanism.

【０００２】[0002]

【従来の技術】ベンチュリ、絞り弁を有しエンジンが要
求する所要量の混合気を供給する吸気通路の絞り弁下流
側に補助通路を接続し、エンジンが冷えた状態のときに
この補助通路より混合気を供給して始動性を高めること
は広く知られている。2. Description of the Related Art An auxiliary passage is connected to a downstream side of a throttle valve of an intake passage having a venturi and a throttle valve for supplying a required amount of air-fuel mixture required by an engine, and the auxiliary passage is connected to the auxiliary passage when the engine is cold. It is widely known to supply an air-fuel mixture to enhance startability.

【０００３】前記の補助通路を含む始動機構は、空気取
入口から延びる空気通路部と浮子式またはダイヤフラム
式の定燃料室から延びる燃料通路部とそれらの合流個所
から吸気通路の絞り弁下流側へ向かって延びる混合気通
路部とからなる補助通路と、この補助通路を開閉して空
気と燃料の供給遮断を同時に行なう開閉弁とを具えてい
る。The starting mechanism including the above-mentioned auxiliary passage is provided with an air passage extending from the air intake, a fuel passage extending from the floating or diaphragm type constant fuel chamber, and a junction thereof to a downstream side of the throttle valve in the intake passage. An auxiliary passage comprising an air-fuel mixture passage extending toward the air passage, and an on-off valve for opening and closing the auxiliary passage to simultaneously shut off supply of air and fuel are provided.

【０００４】そして、自動車用エンジン向け気化器にお
いては、開閉弁は例えば実開昭５４−８７３２０号公報
に記載されているように、エンジンの運転状態に応じて
マイクロコンピュータが指令する信号により作動する電
磁駆動としたものが多い。In a carburetor for an automobile engine, the on-off valve is operated by a signal instructed by a microcomputer in accordance with the operating state of the engine, as described in, for example, Japanese Utility Model Laid-Open Publication No. 54-87320. Many are electromagnetically driven.

【０００５】一方、汎用エンジン向け気化器において
は、開閉弁は手動によって開閉操作するのが普通である
が、閉弁方向へ働くばねを具えた直線動形の開閉弁を使
用してアイドル位置の絞り弁レバーを係合させることに
よって開弁位置に保持し、絞り弁が開きはじめて吸気通
路より正規の混合気が供給されるようになると同時に係
合が外れて閉弁するようにしたものが特開平８−２８４
７５４号公報に記載されている。On the other hand, in a carburetor for a general-purpose engine, the on-off valve is normally opened and closed manually. The throttle valve lever is held in an open position by engaging the throttle valve, and the throttle valve starts to open, a normal air-fuel mixture is supplied from the intake passage, and at the same time, the engagement is released and the valve is closed. Kaihei 8-284
No. 754.

【０００６】汎用エンジン向け気化器は小形且つ安価で
あることが要求され、補助通路の開閉弁は手動で開弁さ
せるとともに絞り弁レバーを係合させて開弁位置に保持
し或いは係合を外してばね力で閉弁させる、という前記
特開平８−２８４７５４号公報に記載されている始動機
構はこの要求に応えることができる。[0006] A carburetor for a general-purpose engine is required to be small and inexpensive, and the opening and closing valve of the auxiliary passage is manually opened and the throttle valve lever is engaged to hold or release the valve in the open position. The starting mechanism described in JP-A-8-284754, in which the valve is closed by a spring force, can meet this demand.

【０００７】[0007]

【発明が解決しようとする課題】しかしながら、前記の
始動機構は絞り弁がアイドル位置から開きはじめたとき
開閉弁が全開から全閉へと動作し、従って絞り弁がアイ
ドル位置に置かれている状態で始動および暖機運転を行
なうときのみ補助通路を開く。However, when the throttle valve starts to open from the idle position, the opening / closing valve operates from the fully open state to the fully closed state. Open the auxiliary passage only when starting and warming-up.

【０００８】このため、絞り弁が開きはじめたとき一時
的に空燃比や吸入空気量が変動してエンジン運転を不調
にする、という心配がある。また、暖機不充分な時期に
絞り弁を開くと燃料不足によりエンジンが停止する、と
いう心配がある。For this reason, when the throttle valve starts to open, there is a concern that the air-fuel ratio and the amount of intake air may fluctuate temporarily, resulting in malfunction of the engine. In addition, there is a concern that if the throttle valve is opened at a time when the warm-up is insufficient, the engine may be stopped due to a shortage of fuel.

【０００９】本発明は汎用エンジン向け気化器に設けら
れた前述の始動機構によると、絞り弁がアイドル位置に
置かれているときのみ補助通路から混合気が供給される
構成であるため、絞り弁が開きはじめたときエンジンエ
ンジン運転を不調にしたり、暖機不充分のためエンジン
を停止させたりする心配がある、という前記課題を解決
し、絞り弁が或る開度に開かれるまで補助通路から混合
気を供給してエンジンを安定よく運転させることができ
る始動機構を具えさせることを目的として発明されたも
のである。According to the present invention, according to the starting mechanism provided in the carburetor for a general-purpose engine, the air-fuel mixture is supplied from the auxiliary passage only when the throttle valve is at the idle position. When the opening of the engine begins to open, the engine engine malfunctions or there is a concern that the engine may be stopped due to insufficient warm-up. The present invention has been devised to provide a starting mechanism capable of supplying an air-fuel mixture and operating the engine stably.

【００１０】[0010]

【課題を解決するための手段】本発明は空気取入口から
延びる空気通路部と定燃料室から延びる燃料通路部とそ
れらの合流個所から延び吸気通路の絞り弁下流側に接続
された混合気通路部とからなる補助通路と、手動で開弁
方向へ動かされる弁体と弁体を閉弁方向へ付勢したばね
部材とを有し補助通路を開閉して空気と燃料の供給遮断
を同時に行なう開閉弁とを有する始動機構を具えた気化
器がもっている前記課題を解決するために次のようにし
た。SUMMARY OF THE INVENTION The present invention provides an air passage extending from an air intake, a fuel passage extending from a constant fuel chamber, and a mixture passage extending from a junction thereof and connected downstream of a throttle valve of an intake passage. And an auxiliary passage having a valve body that is manually moved in the valve opening direction and a spring member that urges the valve body in the valve closing direction. The auxiliary passage is opened and closed to simultaneously shut off supply of air and fuel. In order to solve the above-mentioned problems of the carburetor provided with a starting mechanism having an on-off valve, the following is made.

【００１１】即ち、開閉弁の弁体を開弁位置に拘束する
保持手段を具えさせ、この保持手段は絞り弁が或る開度
に開かれたとき絞り弁レバーによって弁体の拘束を解除
する構成としたものである。この構成により、絞り弁が
アイドル位置と或る開度位置との間に在るとき補助通路
から混合気が供給され、冷えた状態のエンジンの始動お
よび暖機運転が確実に行なわれるばかりか、この状態で
の加速運転も行なうことが可能となり、また絞り弁がか
なり大きく開かれたとき補助通路が閉止されるので、吸
気通路からの正規の混合気のみによる運転に円滑に切換
えることができるようになった。That is, a holding means for restraining the valve element of the on-off valve at the valve opening position is provided, and this holding means releases the restriction of the valve element by the throttle valve lever when the throttle valve is opened to a certain opening. It is configured. With this configuration, when the throttle valve is between the idle position and a certain opening position, the air-fuel mixture is supplied from the auxiliary passage, and not only the start and the warm-up operation of the cold engine are surely performed, but also, Acceleration operation in this state can also be performed, and the auxiliary passage is closed when the throttle valve is opened considerably, so that the operation can be smoothly switched to only the normal mixture from the intake passage. Became.

【００１２】開閉弁の弁体は回転させることなくそのま
ま直線動させる場合と回転しながら直線動させる場合と
がある。この弁体を含む直線動部分を開弁位置に拘束す
る保持手段は、前者にあっては直線動部分の係合溝とこ
れに嵌脱する拘束部材とからなるものとするのが好適で
ある。また、後者にあっては直線動部分と気化器本体部
分とに対向形成したカムの頂部に設けた係止面とする
か、または直線動部分と絞り弁レバーとに設けた係合用
の段部や突起などとするのが好適である。これらは絞り
弁の或る開度以上で拘束部材を係合溝から脱出させ、或
いは直線動部分を拘束解除方向へ回転させるように、絞
り弁レバーによって動作させられる。The valve body of the on-off valve may be moved linearly without rotation, or may be moved linearly while rotating. In the former, the holding means for restraining the linearly moving portion including the valve body at the valve opening position preferably comprises an engaging groove of the linearly moving portion and a restraining member which fits into and disengages from the engaging groove. . In the case of the latter, a locking surface provided on the top of a cam formed opposite to the linearly moving portion and the carburetor body portion, or an engaging step provided on the linearly moving portion and the throttle valve lever It is preferable to use a projection or the like. These are operated by a throttle valve lever so that the restricting member escapes from the engagement groove at a certain opening degree of the throttle valve or more, and the linearly moving portion is rotated in the restriction releasing direction.

【００１３】更に、弁体が回転しながら直線動するもの
において、開弁位置に拘束したとき絞り弁レバーを押し
て絞り弁をアイドル位置から少し開かせる構成とするこ
とがある。このものは、低速時に大空気量を必要とする
エンジンに対して、補助通路と吸気通路の両方から空気
を送り安定した運転を行なわせることができる。Further, in the case where the valve body moves linearly while rotating, the throttle valve may be slightly opened from the idle position by pressing the throttle valve lever when restrained at the valve opening position. This allows an engine that requires a large amount of air at low speed to send air from both the auxiliary passage and the intake passage to perform a stable operation.

【００１４】[0014]

【発明の実施の形態】図１，２，３，４および５は請求
項１および２に記載した発明の実施の形態を示すもので
あって、チョーク弁２，ベンチュリ３，絞り弁４を有す
る吸気通路５を挟んで気化器本体１の外側面に燃料ポン
プ６と定燃料室１０とが設置されている。1, 2, 3, 4, and 5 show an embodiment of the invention described in claims 1 and 2, which have a choke valve 2, a venturi 3, and a throttle valve 4. A fuel pump 6 and a constant fuel chamber 10 are provided on the outer surface of the carburetor body 1 with the intake passage 5 interposed therebetween.

【００１５】燃料ポンプ６は気化器本体１の一つの側面
にポンプダイヤフラム７，ポンプカバー体８を順に重
ね、ポンプダイヤフラム７を挟んで気化器本体１とポン
プカバー体８とにくぼみを設けてこれらを燃料ポンプ
室，脈圧室とし、エンジンのクランクケースに発生する
脈圧を脈圧室に導入してポンプダイヤフラム７を動作さ
せることにより、燃料タンクの燃料を燃料ポンプ室に吸
込み、次でこれより燃料通路を通って定燃料室１０へと
吐出する、というよく知られた構成であって、燃料ポン
プ室，脈圧室，燃料通路は図解を省略した。In the fuel pump 6, a pump diaphragm 7 and a pump cover body 8 are sequentially stacked on one side of the carburetor body 1, and a recess is provided in the carburetor body 1 and the pump cover body 8 with the pump diaphragm 7 interposed therebetween. Is used as a fuel pump chamber and a pulse pressure chamber, and the pulse pressure generated in the crankcase of the engine is introduced into the pulse pressure chamber to operate the pump diaphragm 7, thereby sucking the fuel in the fuel tank into the fuel pump chamber. This is a well-known configuration in which the fuel is discharged to the constant fuel chamber 10 through the fuel passage, and the fuel pump chamber, the pulse pressure chamber, and the fuel passage are not illustrated.

【００１６】定燃料室１０は気化器本体１のもう一つの
側面に設けたくぼみによって形成され、この側面に重ね
たダイヤフラム１１によってダイヤフラムカバー体１２
の内面に形成した大気室１３と区画されている。このダ
イヤフラム１１の変位に応じて図示しない燃料弁が燃料
通路を開閉することにより、定燃料室１０に一定圧力に
規定した燃料を保有させることも従来からよく知られて
いるものと同じである。The constant fuel chamber 10 is formed by a recess provided on another side of the carburetor body 1, and a diaphragm cover 12 is formed by a diaphragm 11 superposed on this side.
Is partitioned from the atmosphere chamber 13 formed on the inner surface of. A fuel valve (not shown) opens and closes a fuel passage in accordance with the displacement of the diaphragm 11 to cause the constant fuel chamber 10 to hold fuel regulated at a constant pressure, as is well known in the art.

【００１７】定燃料室１０の燃料は主燃料通路１４を通
ってベンチュリ３の最狭部に開口した主ノズル１５から
吸気通路５に吸出され、或いは低速燃料通路１６を通っ
て絞り弁４の側方に開口したアイドルポート１７，スロ
ーポート１８から吸気通路５に吸出される。これらの主
燃料通路１４，低速燃料通路１６には図示しない手動の
調整弁が設けられ、燃料流量を調整することができるよ
うになっているのが普通である。The fuel in the constant fuel chamber 10 is drawn through the main fuel passage 14 from the main nozzle 15 opened at the narrowest portion of the venturi 3 into the intake passage 5, or passes through the low speed fuel passage 16 to the side of the throttle valve 4. The air is sucked into the intake passage 5 from the idle port 17 and the slow port 18 which are opened to the front. The main fuel passage 14 and the low-speed fuel passage 16 are usually provided with a manual adjustment valve (not shown) so that the fuel flow rate can be adjusted.

【００１８】次に、本発明の始動機構を構成する補助通
路２１は、チョーク弁２の上流側において吸気通路５に
開口した空気取入口２２ａを有し吸気通路５の側方をこ
れと平行に延びる空気通路部２２と、定燃料室１０から
吸気通路５の側方をこれと直角に延びる燃料通路部２３
と、これら二つの通路部２２，２３の合流個所から吸気
通路５の側方をこれと平行に延び絞り弁４の下流側にお
いて吸気通路５に開口した混合気通路部２４とによって
形成されている。尚、チョーク弁２をもたない気化器に
あっては、空気取入口２２ａはベンチュリ３の上流側適
所で吸気通路５に開口させる。Next, the auxiliary passage 21 constituting the starting mechanism of the present invention has an air intake 22a opened to the intake passage 5 on the upstream side of the choke valve 2 so that the side of the intake passage 5 is parallel to this. An air passage portion 22 extending from the constant fuel chamber 10 to a side of the intake passage 5 at right angles to the fuel passage portion 23;
And an air-fuel mixture passage portion 24 extending parallel to the side of the intake passage 5 from the junction of the two passage portions 22 and 23 and opening to the intake passage 5 downstream of the throttle valve 4. . In a carburetor without the choke valve 2, the air intake 22 a is opened to the intake passage 5 at a suitable position on the upstream side of the venturi 3.

【００１９】空気通路部２２と混合気通路部２４とは同
一中心線上に配置されており、これらの間にはその中心
線と直交させてシリンダ室状の弁室２６が設けられてい
る。弁室２６の底には通孔２７ａを計量ジェットとした
弁座２７が設置されており、燃料通路部２３はこの通孔
２７ａを経て弁室２６に連通している。The air passage portion 22 and the mixture passage portion 24 are arranged on the same center line, and a cylinder chamber-shaped valve chamber 26 is provided between them at right angles to the center line. A valve seat 27 having a through hole 27a as a measuring jet is installed at the bottom of the valve chamber 26, and the fuel passage portion 23 communicates with the valve chamber 26 through the through hole 27a.

【００２０】弁室２６の気化器本体１の側面に開放した
端部に円筒状の案内部材３４が嵌装固定されており、プ
ランジャ形の弁体２８が弁室２６から案内部材３４の内
孔３４ａに亘って可動に嵌込まれている。弁体２８は弁
座２７に着座したとき燃料通路部２３を閉止すると同時
に空気通路部２２および混合気通路部２４，殊に空気通
路部２２を閉止するように働く。A cylindrical guide member 34 is fitted and fixed to an end of the valve chamber 26 which is open to the side surface of the carburetor body 1, and a plunger-shaped valve body 28 is inserted from the valve chamber 26 into the inner hole of the guide member 34. It is movably fitted over 34a. The valve body 28 functions to close the fuel passage portion 23 when seated on the valve seat 27 and at the same time to close the air passage portion 22 and the mixture passage portion 24, particularly, the air passage portion 22.

【００２１】弁体２８の弁座２７への着座面と反対側の
端面は円錐状の傾斜段部２８ａとされ、それより延びる
操作軸２９の案内部材３４から突出させた軸端に摘み３
０が取付けられている。弁体２８，操作軸２９および摘
み３０は直線動部分３１を構成しており、弁体２８の外
側周面には環状の係合溝３６が設けられているととも
に、案内部材３４の先端壁と操作軸２９に固着したばね
受座３２との間に圧縮コイルばねからなる閉弁用のばね
部材３３が装入されている。The end surface of the valve body 28 opposite to the seating surface on the valve seat 27 is formed as a conical inclined step portion 28a, and a knob 3 is formed on a shaft end protruding from a guide member 34 of an operating shaft 29 extending therefrom.
0 is attached. The valve body 28, the operating shaft 29 and the knob 30 constitute a linearly moving portion 31. An annular engagement groove 36 is provided on the outer peripheral surface of the valve body 28, and the distal end wall of the guide member 34 A valve-closing spring member 33 made of a compression coil spring is inserted between a spring seat 32 fixed to the operation shaft 29.

【００２２】前述の弁室２６，弁座２７，弁体２８，操
作軸２９，摘み３０，ばね部材３３，案内部材３４は開
閉弁２５を構成している。The above-mentioned valve chamber 26, valve seat 27, valve body 28, operating shaft 29, knob 30, spring member 33, and guide member 34 constitute an on-off valve 25.

【００２３】案内部材３４はコ形の切欠溝３７を有して
おり、この切欠溝３７に拘束部材３８が嵌脱可能に嵌込
まれている。即ち、拘束部材３８は切欠溝３７に嵌入す
るコ形の係合部３８ａとその一端より延びるばね受部３
８ｂとを有し、案内部材３４とばね受部３８ｂとの間に
圧縮コイルばねからなる拘束ばね３９が装入されてい
る。The guide member 34 has a U-shaped notch groove 37 into which a restraining member 38 is removably fitted. That is, the restraining member 38 has a U-shaped engaging portion 38 a fitted into the notch groove 37 and the spring receiving portion 3 extending from one end thereof.
8b, and a constraint spring 39 made of a compression coil spring is inserted between the guide member 34 and the spring receiving portion 38b.

【００２４】図２および図３に示す状態、即ち弁体２８
が弁座２７に着座して補助通路２１を閉止していると
き、拘束部材３８の係合部３８ａは操作軸２９の外側周
面に接している。The state shown in FIG. 2 and FIG.
Is seated on the valve seat 27 to close the auxiliary passage 21, the engagement portion 38 a of the restraining member 38 is in contact with the outer peripheral surface of the operation shaft 29.

【００２５】エンジン始動に先立って、摘み３０を持っ
て直線動部分３１をばね部材３３のばね力に逆って引張
ると、弁体２８が弁座２７から離れて空気通路部２２，
燃料通路部２３，混合気通路部２４をお互いに連通させ
る。拘束部材３８は傾斜段部２８ａに沿って切欠溝３７
から抜け出す方向へ動き、弁体２８が全開位置に至った
とき拘束ばね３９のばね力によって係合溝３６に嵌入し
て図４（Ａ），（Ｂ）に示す状態となる。このことによ
り、摘み３０から手を離しても直線動部分３１は開弁位
置に拘束されることとなる。Prior to the start of the engine, when the linearly moving portion 31 is pulled with the knob 30 against the spring force of the spring member 33, the valve body 28 separates from the valve seat 27 and the air passage portions 22,
The fuel passage 23 and the mixture passage 24 communicate with each other. The restraining member 38 is provided with the notch groove 37 along the inclined step portion 28a.
When the valve body 28 reaches the fully open position, the valve body 28 is fitted into the engagement groove 36 by the spring force of the restraining spring 39, and the state shown in FIGS. 4A and 4B is obtained. As a result, even when the hand is released from the knob 30, the linearly moving portion 31 is restricted to the valve opening position.

【００２６】前述の係合溝３６，拘束部材３８，拘束ば
ね３９は開閉弁２５の弁体２８を開弁位置に保持する保
持手段３５を構成しており、エンジンをクランキングさ
せたとき吸気通路５の絞り弁下流側に発生する吸気負圧
によって空気通路部２２，燃料通路部２３から空気、燃
料が吸引されて弁室２６で合流混合し、この混合気が混
合気通路部２４より吸気通路５に吸引されてエンジンに
供給される。The engaging groove 36, the restraining member 38, and the restraining spring 39 constitute a holding means 35 for holding the valve body 28 of the on-off valve 25 at the valve opening position. The air and fuel are sucked from the air passage 22 and the fuel passage 23 by the intake negative pressure generated on the downstream side of the throttle valve 5 and merged and mixed in the valve chamber 26. 5 and supplied to the engine.

【００２７】円板形の絞り弁４を支持している絞り弁軸
４２の気化器本体１から外側方へ突出している軸端部に
は絞り弁レバー４３が固着されている。この絞り弁レバ
ー４３は運転者のアクセル操作によって絞り弁４をアイ
ドル位置から全開位置まで回転させ、また図示しないね
じりコイルばねからなる戻しばねは絞り弁４を開いた位
置からアイドル位置まで回転させる。A throttle valve lever 43 is fixed to a shaft end of the throttle valve shaft 42 supporting the disk-shaped throttle valve 4 and protruding outward from the carburetor body 1. The throttle valve lever 43 rotates the throttle valve 4 from an idle position to a fully open position by a driver's accelerator operation, and a return spring formed of a torsion coil spring (not shown) rotates the throttle valve 4 from an open position to an idle position.

【００２８】絞り弁レバー４３は腕部片４４を有してい
る。この腕部片４４は絞り弁４がアイドル位置から部分
開き位置、一般には全開に近い部分開き位置まで開かれ
たとき拘束部材３８のばね受部３８ｂに当るようになっ
ている。このため、エンジンが冷えた状態での始動およ
び暖機運転に必要な混合気を、絞り弁４がアイドル位置
および或る開き位置のいずれに置かれていても補助通路
２１によって供給することができる。また、エンジンが
冷えた状態で絞り弁４を急に開いて加速運転を行なう場
合も、前記部分開き位置以下に開かれる限りは補助通路
２１が開かれており、冷えたエンジンが要求する量の混
合気を供給することができる。The throttle valve lever 43 has an arm piece 44. The arm piece 44 comes into contact with the spring receiving portion 38b of the restraining member 38 when the throttle valve 4 is opened from the idle position to a partially opened position, generally a partially opened position close to full open. For this reason, the air-fuel mixture required for starting and warming-up when the engine is cold can be supplied through the auxiliary passage 21 regardless of whether the throttle valve 4 is located at the idle position or at a certain open position. . Also, when the throttle valve 4 is suddenly opened while the engine is cold to perform the acceleration operation, the auxiliary passage 21 is opened as long as the throttle valve 4 is opened below the partial opening position. An air-fuel mixture can be supplied.

【００２９】絞り弁４が前記部分開き位置よりも大きく
開かれると、図５に示すように腕部片４４がばね受部３
８ｂを押して係合部３８ａを係合溝３６から脱出させ、
これにより拘束を解かれた直線動部分３１はばね部材３
３に押されて弁体２８が弁座２７に着座するまで前進
し、図２および図３の状態に戻って補助通路２１を閉止
する。以後は、吸気通路５のみによる混合気がエンジン
に供給される。When the throttle valve 4 is opened more than the partial opening position, as shown in FIG.
8b to release the engagement portion 38a from the engagement groove 36,
As a result, the linear moving portion 31 released from the restraint becomes the spring member 3.
3 and is advanced until the valve body 28 is seated on the valve seat 27, and returns to the state of FIGS. 2 and 3 to close the auxiliary passage 21. Thereafter, the air-fuel mixture only through the intake passage 5 is supplied to the engine.

【００３０】なお、絞り弁４がアイドル位置または小さ
い開度位置のときに補助通路２１からの混合気供給が不
要となったとき、一般にはエンジンの暖機運転が完了し
たものと運転者が認定した場合、摘み３０を強く押すか
またはばね受片３８ｂを押すことにより拘束部材３８を
係合溝３６から脱出させて補助通路２１を閉止すること
ができる。When the supply of the air-fuel mixture from the auxiliary passage 21 becomes unnecessary when the throttle valve 4 is at the idle position or the small opening position, the driver generally recognizes that the warm-up operation of the engine has been completed. In this case, pressing the knob 30 or pressing the spring receiving piece 38b causes the restraining member 38 to escape from the engagement groove 36 and close the auxiliary passage 21.

【００３１】次に、図６，７，８は請求項１および３に
記載した発明の実施の形態を示すものであって、補助通
路２１の空気通路部２２と混合気通路部２４との間にこ
れらの中心線と直交させて開閉弁２５の弁室２６が設け
られ、その底に通孔２７ａを計量ジェットとした弁座２
７が設置されていて、燃料通路部２３が通孔２７ａを経
て弁室２６に連通している。Next, FIGS. 6, 7 and 8 show an embodiment of the invention described in claims 1 and 3, wherein an air passage 22 of an auxiliary passage 21 and a mixture passage 24 are provided. A valve chamber 26 of an on-off valve 25 is provided at right angles to these center lines, and a valve seat 2 having a through hole 27a as a metering jet is provided at the bottom thereof.
7, the fuel passage 23 communicates with the valve chamber 26 through the through hole 27a.

【００３２】弁室２６の気化器本体１の側面に開放した
端部に短円筒状の案内部材５４が嵌装固定されており、
弁室２６に嵌装されたピストン形の弁体２８は弁座２７
と案内部材５４の先端面との間で可動とされ、弁座２７
に着座したとき燃料通路部２３を閉止すると同時に空気
通路部２２および混合気通路部２４、殊に空気通路部２
２を閉止する。A short cylindrical guide member 54 is fitted and fixed to an end of the valve chamber 26 which is open to the side surface of the carburetor body 1.
A piston-shaped valve body 28 fitted in the valve chamber 26 is provided with a valve seat 27.
Between the valve seat 27 and the distal end surface of the guide member 54.
When the seat is seated, the fuel passage 23 is closed and at the same time, the air passage 22 and the mixture passage 24, in particular, the air passage 2
2 is closed.

【００３３】弁体２８の弁座２７への着座面と反対側に
は案内部材５４を貫通して弁軸５６が延びており、この
弁軸５６の案内部材５４から突出している軸端部に始動
レバー５７が固着されている。また、弁座２８と案内部
材５４との間には弁軸５６を囲んで圧縮コイルばねから
なる閉弁用のばね部材３３が装入されている。A valve shaft 56 extends through the guide member 54 on the opposite side of the seat surface of the valve body 28 to the valve seat 27. The shaft end of the valve shaft 56 projecting from the guide member 54 The starting lever 57 is fixed. A valve closing spring member 33 made of a compression coil spring is inserted between the valve seat 28 and the guide member 54 so as to surround the valve shaft 56.

【００３４】前述の弁室２６，弁座２７，弁体２８，ば
ね部材３３，弁軸５６，始動レバー５７は回転しながら
直線動する直線動部分５９を構成している。The above-described valve chamber 26, valve seat 27, valve body 28, spring member 33, valve shaft 56, and starting lever 57 constitute a linearly moving portion 59 which linearly moves while rotating.

【００３５】案内部材５４は気化器本体１に固定されて
その一部を構成しており、この案内部材５４および始動
レバー５７の互いに向かい合った端面には傾斜面からな
るカム５５，５８がそれぞれ形成されているとともに、
これらのカム５５，５８の最も突出している部分、即ち
頂部は中心軸線に直角の係止面５５ａ，５８ａとされて
いる。The guide member 54 is fixed to the carburetor body 1 to form a part thereof, and cams 55 and 58 each having an inclined surface are formed on the end faces of the guide member 54 and the starting lever 57 facing each other. Along with
The most protruding portions of these cams 55, 58, that is, the tops, are locking surfaces 55a, 58a perpendicular to the central axis.

【００３６】前述のカム５５，５８の係止面５５ａ，５
８ａは開閉弁２５の弁体２８を開弁位置に保持する保持
手段３５を構成している。The locking surfaces 55a, 5 of the above-described cams 55, 58
8a constitutes holding means 35 for holding the valve body 28 of the on-off valve 25 at the valve opening position.

【００３７】エンジンの始動に先立って図６（Ａ），
（Ｂ）に示す閉弁位置に置かれている始動レバー５７を
手動で図示反時計方向へ回転させると、始動レバー５７
のカム５８の頂部が案内部材５４のカム５５に沿って円
周方向へ移動することによって直線動部分５９は回転し
ながらばね部材３３のばね力に逆って気化器本体１から
抜き出される方向へ移動し、９０度回転したとき係止面
５５ａ，５８ａが互いに重なって図７（Ａ），（Ｂ）に
示す状態となる。Prior to starting the engine, FIG.
When the starting lever 57 placed at the valve closing position shown in (B) is manually rotated counterclockwise in the figure, the starting lever 57
The top of the cam 58 moves in the circumferential direction along the cam 55 of the guide member 54, so that the linearly moving portion 59 rotates and is pulled out of the carburetor body 1 against the spring force of the spring member 33. And when they are rotated 90 degrees, the locking surfaces 55a and 58a overlap with each other, resulting in the state shown in FIGS. 7A and 7B.

【００３８】弁体２８は係止面５５ａ，５８ａの互いの
重なりによって開弁位置に保持され、エンジンの始動お
よび暖機運転に必要な混合気を補助通路２１により供給
することができる。The valve body 28 is held at the valve-open position by the overlapping of the locking surfaces 55a and 58a, so that the air-fuel mixture necessary for starting the engine and warming up can be supplied through the auxiliary passage 21.

【００３９】始動レバー５７は外側周縁に係合段部５７
ａを有しており、また、絞り弁軸４２の軸端部に固着さ
れている絞り弁レバー４３は腕部片４５を有している。
この腕部片４４は絞り弁４が全開に近い部分開き位置ま
で開かれたとき係合段部５７ａに当り、それより図８に
示す全開位置となるまで始動レバー５７を押して図７，
８の時計方向へ回転させる。このことにより、始動レバ
ー５７の係止面５８ａが案内部材５４の係止面５５ａか
ら外れ、拘束を解かれた直線動部分５９はばね部材３３
に押されてカム５５の傾斜に従い弁体２８が弁座２７に
着座するまで前進し、図６（Ａ）の状態に戻って補助通
路２１を閉止する。The starting lever 57 has an engagement step 57 on the outer periphery.
The throttle valve lever 43 fixed to the shaft end of the throttle valve shaft 42 has an arm piece 45.
The arm piece 44 hits the engagement step 57a when the throttle valve 4 is opened to a partially open position close to full open, and then pushes the starting lever 57 until the throttle valve 4 reaches the fully open position shown in FIG.
Rotate 8 clockwise. As a result, the locking surface 58a of the starting lever 57 is disengaged from the locking surface 55a of the guide member 54, and the unrestricted linear moving portion 59 is released from the spring member 33.
6A, the valve body 28 advances according to the inclination of the cam 55 until the valve body 28 is seated on the valve seat 27, and returns to the state of FIG. 6A to close the auxiliary passage 21.

【００４０】開閉弁２５が閉弁を開始する時期は、係合
段部５７ａと腕部片４５との位置関係や係止面５５ａ，
５８ａの円周方向長さによって任意に設定することがで
き、エンジンが冷えた状態での始動、暖機運転および加
速運転を補助通路２１から供給される混合気によって円
滑に行なうことが可能となる。The timing at which the on-off valve 25 starts closing is determined by the positional relationship between the engagement step 57a and the arm piece 45, the locking surface 55a,
It can be arbitrarily set according to the circumferential length of 58a, and it is possible to smoothly start, warm up, and accelerate the engine in a cold state by the mixture supplied from the auxiliary passage 21. .

【００４１】尚、絞り弁レバー４３によることなく、始
動レバー５７を手で回転させることにより直線動部分５
９の拘束を解き、任意の時期に補助通路２１を閉止する
ことができる。It is to be noted that the rotation of the starter lever 57 by hand without using the throttle valve lever 43 allows
9, the auxiliary passage 21 can be closed at any time.

【００４２】図９は請求項１および４に記載した発明に
おける、殊に開閉弁の弁体を開弁位置に保持する保持手
段３５の実施の形態を示すものであって、図６，７，８
に示した開閉弁２５の直線動部分５９の一部である始動
レバー５７に設けた係止突起６１と、絞り弁レバー４３
に設けた係止段部６２とによって保持手段３５が構成さ
れている。FIG. 9 shows an embodiment of the holding means 35 for holding the valve element of the on-off valve in the valve opening position, in particular, in the first and fourth aspects of the present invention. 8
A locking projection 61 provided on a starting lever 57 which is a part of the linearly moving portion 59 of the on-off valve 25 shown in FIG.
The holding means 35 is constituted by the locking step portion 62 provided in the above.

【００４３】図９（Ａ）は開閉弁２５が補助通路２１を
閉じており、エンジンが停止または運転されているとき
の始動レバー５７，絞り弁レバー４３の位置関係の一つ
を示している。始動レバー５７は図６（Ｂ）に示した閉
弁位置における始動レバー５７と同一位相となってい
る。FIG. 9A shows one of the positional relationships between the starting lever 57 and the throttle valve lever 43 when the on-off valve 25 closes the auxiliary passage 21 and the engine is stopped or running. The starting lever 57 has the same phase as the starting lever 57 in the valve closing position shown in FIG.

【００４４】冷えたエンジンを始動させるにあたって始
動レバー５７を手で図示反時計方向へ９０度回転させる
と、カムによって直線動部分５９が回転しながら気化器
本体から抜き出される方向へ移動して開弁するととも
に、係止突起６１がアイドル位置の絞り弁レバー４３の
係止段部６２に係合し、図９（Ｂ）に示す状態となる。
この状態で補助通路から供給される混合気によって始動
および暖機運転が行なわれる。When the cold start of the engine is started, when the start lever 57 is rotated by 90 degrees in the counterclockwise direction in the figure by hand, the linearly moving portion 59 is rotated by the cam and moved in the direction of being pulled out of the carburetor body to open. At the same time, the locking projection 61 engages with the locking step 62 of the throttle valve lever 43 at the idle position, and the state shown in FIG. 9B is obtained.
In this state, the start-up and warm-up operation are performed by the mixture supplied from the auxiliary passage.

【００４５】絞り弁をアイドル位置から開きはじめると
き、絞り弁レバー４３は図示反時計方向へ回転し、係止
突起６１と係止段部６２との係合深さが次第に浅くな
り、始動レバー５７は図示時計方向へ回転するようにな
るが、絞り弁レバー４３に拘束されて開弁状態を維持す
る。When the throttle valve starts to be opened from the idle position, the throttle valve lever 43 rotates counterclockwise in the drawing, and the engagement depth between the locking projection 61 and the locking step 62 gradually decreases, and the starting lever 57 Is rotated clockwise in the figure, but is kept open by being restricted by the throttle valve lever 43.

【００４６】絞り弁レバー４３が更に絞り弁開き方向へ
回転すると、係止段部６２が係止突起６１から外れて図
９（Ｃ）に示す拘束が解かれた状態となる。以後はカム
と閉弁用ばね部材とによって図６，図７に示した形態の
ものと同じ動作で開閉弁が閉弁位置となる。When the throttle valve lever 43 further rotates in the throttle valve opening direction, the locking step 62 is disengaged from the locking projection 61, and the restraint shown in FIG. 9C is released. Thereafter, the opening and closing valve is brought to the valve closing position by the same operation as that shown in FIGS. 6 and 7 by the cam and the valve closing spring member.

【００４７】係止突起６１と係止段部６２との係合深さ
を適宜に設定することにより、アイドル位置からの加速
運転を補助通路を開いたまま行なうことができる。By appropriately setting the engagement depth between the locking projection 61 and the locking step 62, the acceleration operation from the idle position can be performed with the auxiliary passage open.

【００４８】尚、図９に示した形態のものにおいて、閉
弁用のばね部材を圧縮コイルばねに代えてトーションば
ねとし、また先の形態で保持手段３５としたカムの係止
面をなくすことにより、係止段部６２が係止突起６１か
ら外れたとき直線動部分５９は直ちに閉弁方向へ動作
し、拘束解除が確実に行なわれる。In the embodiment shown in FIG. 9, the torsion spring is used in place of the compression coil spring for the valve-closing spring member, and the retaining surface of the cam used as the holding means 35 in the previous embodiment is eliminated. Accordingly, when the locking step 62 is disengaged from the locking projection 61, the linearly moving portion 59 immediately operates in the valve closing direction, and the release of the constraint is reliably performed.

【００４９】図１０は請求項１および５に記載した発明
における、殊に開閉弁の弁体を開弁位置に保持する保持
手段３５の図９とは異なる実施の形態を示すものであっ
て、図６，７，８に示した開閉弁２５の直線動部分５９
の一部である始動レバー５７に設けた係止くぼみ６４
と、絞り弁レバー４３に設けた係止突部６５とによって
保持手段３５が構成されている。FIG. 10 shows an embodiment different from that of FIG. 9 of the holding means 35 for holding the valve element of the on-off valve in the valve opening position in the first and fifth aspects of the present invention. Linear moving part 59 of the on-off valve 25 shown in FIGS.
Locking recess 64 provided in the starting lever 57 which is a part of
And the locking projection 65 provided on the throttle valve lever 43 constitute the holding means 35.

【００５０】尚、図１０に示した形態のものは、直線動
部分５９が閉弁位置から開弁位置に移動するとき、前記
図６，７，８に示した形態のものおよび図９に示した形
態のものが反時計方向へ回転させるのに対して、時計方
向へ回転させる点で相違している。In the embodiment shown in FIG. 10, when the linearly moving portion 59 moves from the valve closing position to the valve opening position, the embodiment shown in FIGS. 6, 7, and 8 and the embodiment shown in FIG. The difference is that the above configuration rotates counterclockwise, whereas the configuration rotates clockwise.

【００５１】図１０（Ａ）は開閉弁が補助通路を閉じて
おり、エンジンが停止または運転されているときの始動
レバー５７，絞り弁レバー４３の位置関係の一つを示し
ている。FIG. 10A shows one of the positional relationships between the starting lever 57 and the throttle valve lever 43 when the on-off valve closes the auxiliary passage and the engine is stopped or running.

【００５２】冷えたエンジンを始動させるにあたって、
始動レバー５７を手で図示時計方向へ９０度回転させる
と、カムによって直線動部分５９が回転しながら気化器
本体から抜き出される方向へ移動して開弁する。始動レ
バー５７は回転の終り時期にアイドル位置の絞り弁レバ
ー４３を押し、絞り弁を少し開かせて係止くぼみ６４が
絞り弁レバー４３の係止突部６５に嵌合し、図１０
（Ｂ）に示す状態となる。When starting a cold engine,
When the starting lever 57 is manually rotated clockwise by 90 degrees in the figure, the cam moves the linearly moving portion 59 in the direction in which it is withdrawn from the carburetor body and opens the valve. The starting lever 57 pushes the throttle valve lever 43 in the idle position at the end of the rotation to slightly open the throttle valve, and the locking recess 64 fits into the locking projection 65 of the throttle valve lever 43, as shown in FIG.
The state shown in FIG.

【００５３】絞り弁レバー４３は絞り弁を閉弁させる戻
しばねによってアイドル位置へ向かう回転力が加えられ
ており、係止突部６５の一つの面６５ａが始動レバー５
７の図示反時計方向へ回転する動きを阻止するストッパ
として働く。この状態で補助通路から供給させる混合気
に、絞り弁が少し開かれた正規の吸気通路から供給され
る混合気が加算されてエンジンの始動および暖機運転が
行なわれる。The throttle valve lever 43 is applied with a rotational force toward the idle position by a return spring that closes the throttle valve.
7 serves as a stopper for preventing the movement of the counterclockwise rotation of the counterclockwise direction 7. In this state, the mixture supplied from the normal intake passage with the throttle valve slightly opened is added to the mixture supplied from the auxiliary passage, and the engine is started and the warm-up operation is performed.

【００５４】この形態のものは、アイドル運転時に補助
通路のみによるものよりも大量の混合気を供給するの
で、ブロア運転用エンジンのように低速でもかなり大き
な出力を必要とするエンジンに対して有効である。Since this embodiment supplies a larger amount of air-fuel mixture during idling than that provided only by the auxiliary passage, it is effective for an engine that requires a considerably large output even at a low speed, such as a blower engine. is there.

【００５５】絞り弁を図１０（Ｂ）に示されている始動
位置から開きはじめるとき、絞り弁レバー４３は図示反
時計方向へ回転し、係止くぼみ６４と係止突部６５との
嵌合深さが次第に浅くなるが、始動レバー５７は絞り弁
レバー４３に拘束されて開弁状態を維持する。When the throttle valve is started to be opened from the starting position shown in FIG. 10B, the throttle valve lever 43 rotates counterclockwise in the drawing, and the engagement between the locking recess 64 and the locking projection 65 is achieved. Although the depth gradually decreases, the starting lever 57 is restrained by the throttle valve lever 43 and maintains the valve open state.

【００５６】絞り弁レバー４３が更に絞り弁開き方向へ
回転すると、係止突部６５が係止くぼみ６４から外れて
図１０（Ｃ）に示す拘束が解かれた状態となる。以後は
カムと閉弁用ばね部材とによって図６，７，８に示した
形態のものと同様の動作で開閉弁が閉弁位置となる。ま
た、係止くぼみ６４と係止突部６５との嵌合深さを適宜
に設定することにより、始動位置からの加速運転を補助
通路２１を開いたまま行なうことができる。When the throttle valve lever 43 further rotates in the throttle valve opening direction, the locking projection 65 is disengaged from the locking recess 64, and the restraint shown in FIG. 10C is released. Thereafter, the opening and closing valve is brought to the closed position by the cam and the valve-closing spring member in the same operation as in the embodiment shown in FIGS. In addition, by appropriately setting the fitting depth between the locking recess 64 and the locking projection 65, the acceleration operation from the starting position can be performed with the auxiliary passage 21 kept open.

【００５７】尚、図１０に示した形態のものにおいても
閉弁用のばね部材をトーションばねとし、またカムの係
止面をなくして係止突部６５が係止くぼみ６４から外れ
たとき拘束解除が確実に行なわれるようにすることがで
きる。Also in the embodiment shown in FIG. 10, the spring member for closing the valve is a torsion spring, and the locking surface of the cam is eliminated so that the locking projection 65 is disengaged from the locking recess 64 when it is released. The release can be ensured.

【００５８】[0058]

【発明の効果】以上のように、本発明によると正規の吸
気通路とは別に設けた補助通路によって絞り弁がアイド
ル位置から或る開度に開かれるまで混合気が供給され、
殊に補助通路を閉じたときの混合気供給の切換が良好に
行なわれてエンジンを安定よく運転することができるも
のである。As described above, according to the present invention, the air-fuel mixture is supplied by the auxiliary passage provided separately from the regular intake passage until the throttle valve is opened from the idle position to a certain opening.
In particular, when the auxiliary passage is closed, the supply of the air-fuel mixture is properly switched, so that the engine can be operated stably.

【００５９】加えて、本発明によると補助通路を開いた
状態での加速運転を行なうことや始動時の混合気増量を
計ることができ、エンジンの多様な要求に対応すること
が可能となる。In addition, according to the present invention, it is possible to perform an acceleration operation with the auxiliary passage open, and to measure an increase in the amount of air-fuel mixture at the time of starting, so that it is possible to meet various requirements of the engine.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第一の実施の形態を示す一部切截した
正面図。FIG. 1 is a partially cutaway front view showing a first embodiment of the present invention.

【図２】図１のＸ−Ｘ線に沿う断面図FIG. 2 is a cross-sectional view taken along line XX of FIG.

【図３】図２のＹ−Ｙ線に沿う拡大断面図。FIG. 3 is an enlarged sectional view taken along line YY of FIG. 2;

【図４】第一の実施の形態における開閉弁が開弁した状
態を示しており、（Ａ）は図３と同様の断面図、（Ｂ）
は（Ａ）の一部切截した正面図。4A and 4B show a state where an on-off valve according to the first embodiment is opened, and FIG. 4A is a cross-sectional view similar to FIG. 3, and FIG.
(A) is a partially cut front view of (A).

【図５】第一の実施の形態における保持手段が解除され
た状態を説明する図４（Ｂ）と同様の正面図。FIG. 5 is a front view similar to FIG. 4B, illustrating a state in which the holding unit in the first embodiment is released.

【図６】本発明の第二の実施の形態における開閉弁が閉
弁した状態を示しており、（Ａ）は断面図、（Ｂ）は一
部切截した正面図。6A and 6B show a state in which an on-off valve according to a second embodiment of the present invention is closed, wherein FIG. 6A is a cross-sectional view and FIG. 6B is a partially cut-away front view.

【図７】第二の実施の形態における開閉弁を開弁した状
態を示しており、（Ａ）は断面図、（Ｂ）は正面図。7A and 7B show a state in which an on-off valve according to a second embodiment is opened, wherein FIG. 7A is a cross-sectional view and FIG. 7B is a front view.

【図８】第二の実施の形態における保持手段が解除され
た状態を説明する図７（Ｂ）と同様の正面図。FIG. 8 is a front view similar to FIG. 7B, illustrating a state in which a holding unit according to the second embodiment is released.

【図９】本発明の第三の実施の形態における保持手段と
その動作を説明する正面図。FIG. 9 is a front view illustrating a holding unit and its operation according to a third embodiment of the present invention.

【図１０】本発明の第四の実施の形態における保持手段
とその動作を説明する正面図。FIG. 10 is a front view illustrating a holding unit and an operation thereof according to a fourth embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１ 気化器本体， ４ 絞り弁， ５ 吸気通路， １
０ 定燃料室， ２１補助通路， ２２ 空気通路部，
２３ 燃料通路部， ２４ 混合気通路部， ２５
開閉弁， ２８ 弁体， ３３ ばね部材， ３５ 保
持手段， ４３ 絞り弁レバー，1 carburetor body, 4 throttle valve, 5 intake passage, 1
0 constant fuel chamber, 21 auxiliary passage, 22 air passage,
23 fuel passage, 24 mixture passage, 25
On-off valve, 28 valve element, 33 spring member, 35 holding means, 43 throttle valve lever,

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 空気取入口から延びる空気通路部と定燃
料室から延びる燃料通路部とそれらの合流個所から延び
吸気通路の絞り弁下流側に接続された混合気通路部とか
らなる補助通路と、手動で開弁方向へ動かされる弁体と
前記弁体を閉弁方向へ付勢したばね部材とを有し前記補
助通路を開閉して空気と燃料の供給遮断を同時に行なう
開閉弁とを有する始動機構を具えた気化器において；前
記弁体を開弁位置に拘束する保持手段を具え、前記保持
手段は前記絞り弁が或る開度に開かれたとき絞り弁レバ
ーによって前記弁体の拘束を解く構成とされている；こ
とを特徴とする気化器。1. An auxiliary passage comprising an air passage extending from an air intake, a fuel passage extending from a constant fuel chamber, and a mixture passage extending from a junction thereof and connected to a throttle valve downstream of an intake passage. An opening / closing valve that has a valve body that is manually moved in the valve opening direction and a spring member that urges the valve body in the valve closing direction, and that opens and closes the auxiliary passage to simultaneously shut off supply of air and fuel. A carburetor having a starting mechanism; holding means for restraining the valve body in an open position, wherein the holding means restrains the valve body by a throttle valve lever when the throttle valve is opened to a certain opening. A vaporizer. 【請求項２】 前記開閉弁の弁体は直線動させられ、前
記保持手段は前記弁体を含む直線動部分の外側周面に設
けた係合溝とこの係合溝に嵌脱可能とされ且つ嵌入方向
のばね力が付勢された拘束部材とを具え、前記絞り弁レ
バーは前記絞り弁の或る開度以上で前記拘束部材を前記
係合溝から脱出させて前記直線動部分の拘束を解く方向
へ動かす腕部片を有している請求項１に記載した始動機
構を具えた気化器。2. The valve body of the on-off valve is linearly moved, and the holding means is adapted to be fitted into and disengaged from an engaging groove provided on an outer peripheral surface of a linearly moving portion including the valve body. And a restricting member urged by a spring force in a fitting direction, wherein the throttle valve lever releases the restricting member from the engagement groove when the throttle valve has a certain opening degree or more, and restricts the linearly moving portion. A vaporizer having a starting mechanism according to claim 1, further comprising an arm piece for moving the arm in a direction in which the armature is released. 【請求項３】 前記開閉弁の弁体はこの弁体を含む直線
動部分と気化器本体部分とに対向形成したカムに従う前
記直線動部分の回転に伴って直線動させられ、前記保持
手段は前記カムの頂部に形成した互いに重なる係止面か
らなり、前記絞り弁レバーは前記絞り弁の或る開度以上
で前記直線動部分の前記係止面の重なりによる拘束を解
く方向へ回転させる腕部片を有している請求項１に記載
した始動機構を具えた気化器。3. The valve body of the on-off valve is linearly moved with the rotation of the linearly moving part following a cam formed opposite to a linearly moving part including the valve body and a carburetor main body, and the holding means is An arm for rotating the throttle valve lever in a direction of releasing the constraint due to the overlapping of the locking surfaces of the linearly moving portion when the throttle valve has a certain opening degree or more; A carburetor having a starting mechanism according to claim 1 having a piece. 【請求項４】 前記開閉弁の弁体はこの弁体を含む直線
動部分と気化器本体部分とに対向形成したカムに従う前
記直線動部分の回転に伴って直線動させられ、前記保持
手段は前記直線動部分に設けた係止突起と絞り弁レバー
に設けた係止段部とからなり、前記絞り弁レバーは前記
絞り弁の或る開度以上で前記係止段部の前記係止突起と
の係合による拘束を解く構成とされている請求項１に記
載した始動機構を具えた気化器。4. The valve body of the on-off valve is linearly moved with rotation of the linearly moving part following a cam formed opposite to a linearly moving part including the valve body and a carburetor main body, and the holding means is A locking projection provided on the linearly moving portion and a locking step provided on the throttle valve lever, wherein the throttle valve lever is provided with the locking projection of the locking step at a certain opening degree or more of the throttle valve. The carburetor provided with a starting mechanism according to claim 1, wherein the carburetor is configured to release a restriction due to engagement with the carburetor. 【請求項５】 前記開閉弁の弁体はこの弁体を含む直線
動部分と気化器本体部分とに対向形成したカムに従う前
記直線動部分の回転に伴って直線動させられ、前記保持
手段は前記直線動部分に設けた係止くぼみと絞り弁レバ
ーに設けた係止突部とからなり、前記絞り弁レバーは絞
り弁をアイドル位置から少し開いた位置で前記係止突部
に前記係止くぼみを嵌合して前記弁体を開弁位置に拘束
し、前記絞り弁の或る開度以上で前記拘束を解く構成と
されている請求項１に記載した始動機構を具えた気化
器。5. The valve body of the on-off valve is linearly moved with the rotation of the linearly moving part following a cam formed opposite to a linearly moving part including the valve body and a carburetor main body, and the holding means is The throttle valve lever comprises a locking recess provided on the linearly moving portion and a locking projection provided on the throttle valve lever. The throttle valve lever is configured to lock the throttle valve with the locking projection at a position slightly opened from an idle position. 2. A carburetor having a starting mechanism according to claim 1, wherein said valve body is restrained at a valve opening position by fitting a recess, and said restraint is released when said throttle valve has a certain opening degree or more.